Technical Field
The present invention relates to an image processing technique for displaying image data on a head-mounted display and the like.
Background Art
A technique for a viewer to look at an image by using a head-mounted display (also referred to herein as an HMD) that is fixed to the viewer's head is known. Further, eyewear displays and the like are currently known. Image data displayed on an HMD is cut from an image in all directions on each occasion, and the image, which serves as the source, is also called an environment map. An environment map can be obtained by using a method of image capturing with a fisheye lens or a method of capturing an image of light reflected from a mirror ball with a camera, for example.
Japanese Patent Laid-Open No. 2013-254251 discloses a method of detecting an action of a viewer by using a sensor built in an HMD, scrolling a displayed image in accordance with an operation corresponding to a motion of the viewer's head, and displaying the image.
As a result of the recent increasingly higher resolution of display images, the volume of image data needed for display becomes larger, and reading and decoding of image data for display on an HMD takes longer. Therefore, with the method disclosed in Japanese Patent Laid-Open No. 2013-254251, even if a viewer moves their head to face a direction in which the viewer wants to look, image data that the viewer wants to look at might not be smoothly displayed.